It’s no secret that transition cows are some of the most vulnerable animals on a dairy. The physiological changes and stresses surrounding calving can disrupt immune function and leave cows susceptible to a variety of disorders.

Pankowski joel
Manager, Field Technical Services / Arm & Hammer Animal Nutrition Group

These disorders can lead to serious management challenges later in lactation – like greater days open and lower pregnancy rates, as well as cows prematurely leaving the herd.

Furthermore, these disorders are expensive. For example, a single case of metritis, an all-too-common disease that occurs during the transition period, may cost as much as $354.

That’s why it’s so important to prevent rather than treat transition cow disorders. Providing proper nutrition and management during this critical timeframe is one of the best ways to accomplish this goal.

One proven nutritional tool is to feed bypass Omega-3 and Omega-6 essential fatty acids (EFAs). Research repeatedly shows that these EFAs have a positive impact on immune function and reproductive performance when adequately and properly supplied to the cow.


Case study
A recent on-farm case study that included more than 2,000 cows on two New York dairies looked at the impact of feeding EFAs on immune function and resulting influence on reproductive performance and milk production.

The premise was if a dairy could increase immune function and cows’ ability to fight disease in early lactation via improved nutrition, these healthier cows would enable the dairy to improve reproduction and production performance and efficiencies.

To verify this thought, these EFAs were substituted for other dietary fat sources from 21 days prepartum to 100 days postpartum, and all diets were equal in energy content.

Cow performance in the treatment group was tracked for nine months and compared against herd baseline data from the same months a year prior.

DHIA test results, in conjunction with Dairy Comp 305 records, were used to collect and monitor data for the following parameters:

• Individual cow blood β-hydroxybutyric acid (BHBA) at seven days postpartum

• Adjusted first milk yield

• First linear somatic cell score (SCS)

• First-service conception rate

• Incidence of early embryonic death at up to 35 days post-insemination

BHBA significance
It is important to note that individual cow BHBA levels were of primary interest when examining the data due to their impact on immune function.

Blood levels of BHBA are useful indicators of the ability of cows to deal with metabolic challenges in the transition period – like a cow’s success in adapting to negative energy balance.

In addition, increased concentrations of BHBA at calving have been associated with increased risk of disease and impaired early reproductive performance.


With that in mind, here’s what the data showed.

Cows fed EFAs prepartum and postpartum exhibited significant reductions in early embryonic death (67 percent), BHBA levels (44 percent) and first linear somatic cell score (12 percent), as illustrated by Table 1 .

Management at the cooperating dairies also felt that fewer health issues resulted in higher employee satisfaction and attitudes.

In addition, as you should expect with healthier


cows, reproductive performance, milk production and component yields also increased.

Cows fed EFAs had significantly higher conception and pregnancy rates.

They produced more than 6 pounds more milk per day (a 4-pound increase of fat-corrected milk) and pounds of fat and pounds of protein also rose.

The bottom line
Using a partial budget for the dairies, these improvements in immune response, reproductive performance and milk production carried a significant economic advantage.

The overall net benefit of feeding Omega-3 and Omega-6 EFAs for these operations was $176 per cow per year, or a 15-to-1 net benefit ratio.

Similar economic analyses for herds in other areas of the country using local milk price data have also resulted in positive net benefit ratios from including EFAs in prepartum and postpartum rations.

Even considering the economic response based on improved reproduction alone, the addition of these EFAs to the diet resulted in a 3-to-1 net benefit ratio.

In conclusion, the field study demonstrates the positive impact of EFAs on postpartum immune function in lactating dairy cattle and reinforces the premise that healthier cows perform better.

The results are consistent with previous research in which animals with increased BHBA around parturition experienced a higher risk of milk loss at the first DHIA test and impaired early lactation reproductive performance. PD

References omitted due to space but are available upon request. Click here to email an editor.


Joel Pankowski
Manager Field Technical Services
Arm & Hammer Animal Nutrition Group